Rigid Connection of Bones
I figured out a solution and it's really simple. Since the big bone has the same movement as the bone labeled "crank", I really don't need it. I made a link object the length of both "crank" and the big bone and made that a child of "crank". Then I made the origin of the link object at the top of where the big bone was and I built the second armature (not shown) off that point. Then I made the connecting bone copy the location of the link object.